Ibopamine provocative test and glaucoma: consideration of factors that may influence the examination

To evaluate factors that may influence the ibopamine provocative test for the diagnosis of glaucoma.

Two Ibopamine (3,4 di-isobutyrylester of N-methyldopamine) 2% eyedrops were instilled 5 minutes apart in one eye selected at random in both glaucoma and normal subjects. The intraocular pressure (IOP) was assessed prior to the drops and 30, 60 and 180 minutes after instillation. The test was considered positive when there was an IOP increase of greater than 4 mmHg at any one of the timepoints. The amount of IOP change was compared to the severity of glaucomatous visual field loss and to the types of medical treatment.

The sensitivity (glaucoma patients with a positive result) and specificity (normal individuals with a negative result) of the Ibopamine test was 87 and 95%, respectively. Glaucoma patients using prostaglandin analogues did not have a significant IOP elevation.

The Ibopamine provocative test may be an auxiliary test in glaucoma diagnosis. Concurrent use of prostaglandin analogues reduces the test's sensitivity.